Summary My Brother and I Are Rivals?! from Kainu Manga
My Brother and I Are Rivals?! summary: While amateur photographer Jiang Xianyu was working in a coffee shop, a woman appeared, shining light in her boring daily life. At the same time, Xianyu secretly took photos of her, making her unconsciously fall for her. However, after being found taking her secret photo, she was discovered, making her life turn upside down. And, it turns out that she's the girlfriend of her brother.. My Brother and I Are Rivals?! Those Sibling's Girl 我和哥哥是情敌？！ 그 남매의 그녀